CC BY 4.0Lang, NicolaNicolaLangMathes, NiklasNiklasMathesGötze, ArneArneGötzeReinke, PhilippPhilippReinkeSchreyvogel, ChristophChristophSchreyvogelIannucci, RobertRobertIannucciGiese, ChristianChristianGieseVidal, XavierXavierVidalKnittel, PeterPeterKnittel2024-10-212024-10-212024https://publica.fraunhofer.de/handle/publica/477797https://doi.org/10.24406/h-47779710.1088/1402-4896/ad6f6010.24406/h-477797A challenge to this day in the development of diamond devices for quantum applications is the laterally defined and closely spaced positioning of nitrogen-vacancy centres with exceptional coherence properties. Here, we demonstrate a maskless, implantation-free method for the controlled in-plane positioning of NV centres using a combination of focused ion beam (FIB) milling, plasma etching and nitrogen-doped diamond growth. The Ga⁺ ion beam milling resulted in 1 μm × 1 μm cavities with depths of up to 450 nm, each cavity exhibiting the four [111]-oriented diamond facets after pure hydrogen plasma treatment and a depth of 700 nm. Low-methane, nitrogen-doped chemical vapour deposition (CVD) overgrowth resulted in in situ formation of oriented NV ensembles, exclusively perpendicular to the {111}-planes.ennitrogen vacancyion beam millingCVD overgrowthjournal article